The supersonic flight of a blunt body in a disturbed atmosphere

Numerical analysis of free flow fields around axisymmetric blunt bodies in supersonic fligh

ATS-F radiant cooler contamination test in a hydrazine thruster exhaust

A test was conducted under simulated space conditions to determine the potential thermal degradation of the ATS-F radiant cooler from any contaminants generated by a 0.44-N(0.1-lbf) hydrazine thruster. The radiant cooler, a 0.44-N(0.1-lbf)hydrazine engine, and an aluminum plate simulating the satellite interface were assembled to simulate their flight configuration. The cooler was provided with platinum sensors for measuring temperature, and its surfaces were instrumented with six quartz crystal microbalance units (QCM) to measure contaminant mass deposits. The complete assembly was tested in the molecular sink vacuum facility (Molsink) at the Jet Propulsion Laboratory. This was the first time that a radiant cooler and a hydrazine engine were tested together in a very-high-vacuum space simulator, and this test was the first successful measurement of detectable deposits from hydrazine rocket engine plumes in a high vacuum. The engine was subjected to an accelerated duty cycle of 1 pulse/min, and after 2-hr of operation, the QCMs began to shift in frequency. The tests continued for several days and, although there was considerable activity in the QCMs, the cooler never experienced thermal degradation

Ultralean combustion in general aviation piston engines

The role of ultralean combustion in achieving fuel economy in general aviation piston engines was investigated. The aircraft internal combustion engine was reviewed with regard to general aviation requirements, engine thermodynamics and systems. Factors affecting fuel economy such as those connected with an ideal leanout to near the gasoline lean flammability limit (ultralean operation) were analyzed. A Lycoming T10-541E engine was tested in that program (both in the test cell and in flight). Test results indicate that hydrogen addition is not necessary to operate the engine ultralean. A 17 percent improvement in fuel economy was demonstrated in flight with the Beechcraft Duke B60 by simply leaning the engine at constant cruiser power and adjusting the ignition for best timing. No detonation was encountered, and a 25,000 ft ceiling was available. Engine roughness was shown to be the limiting factor in the leanout

Hydrazine engine plume contamination mapping

Instrumentation for the measurement of plume exhaust specie deposition rates were developed and demonstrated. The instruments, two sets of quartz crystal microbalances, were designed for low temperature operation in the back flow and variable temperature operation in the core flow regions of an exhaust plume. These quartz crystal microbalances performed nominally, and measurements of exhaust specie deposition rates for 8400 number of pulses for a 0.1-lb monopropellant thruster are reported

Study of advanced fuel system concepts for commercial aircraft and engines

The impact on a commercial transport aircraft of using fuels which have relaxed property limits relative to current commercial jet fuel was assessed. The methodology of the study is outlined, fuel properties are discussed, and the effect of the relaxation of fuel properties analyzed. Advanced fuel system component designs that permit the satisfactory use of fuel with the candidate relaxed properties in the subject aircraft are described. The two fuel properties considered in detail are freezing point and thermal stability. Three candidate fuel system concepts were selected and evaluated in terms of performance, cost, weight, safety, and maintainability. A fuel system that incorporates insulation and electrical heating elements on fuel tank lower surfaces was found to be most cost effective for the long term

El cese de la motivación: el síndrome del burnout en deportistas

Partiendo del análisis conceptual del papel de las variables moduladoras cognitivas en los procesos emocionales y motivacionales, en la aparición del síndrome del burnout y su relación con el estrés, se analiza este fenómeno en el contexto deportivo. Tras un breve repaso de su origen en la literatura científica (fundamentalmente sustentada en el ámbito organizacional), nos detenemos en aquellos trabajos e investigaciones que se han centrado en el estudio del síndrome en deportistas, para plantear finalmente la incidencia que la estructura social del deporte puede tener en el proceso motivacional del deportista, siguiendo el planteamiento propuesto por Coakley (1992), para intentar comprender mejor cómo puede aparecer el burnout en los deportistas y cuál puede ser su relación con la ausencia de motivación en este contextoOnce we are studying the conceptual analysis of modulate and cognitive variables in emotional and motivational appearance process of burnout syndrome and its link with the stress, we analyse this phenomenon in the sports context. After a brief review about, its origin in the cientific literature (mainly based in the organizational's field), we have stopped in those works and investigations that have been developed in the study of this syndrome in athletes to pose, finally, the effects that the sport's social structure could have in the process of the motivation about athletes, following Coakley's theory (1992), trying to get more knowledge about how could the burnout appears in athletes and which can be the link between the burnout and the absence of motivation in this contex

The production of sulphites during the fermentation of "Tardana" white wines, and "Tempranillo" rosé and red wines in the D.O. Utiel-Requena

[ES] En el presente trabajo se estudió la producción de sulfitos de diferentes cepas de levaduras comerciales durante la fermentación de vinos blancos, rosados y tintos. Para ello se realizó una experiencia con vinos blancos de la variedad `Tardana¿, y dos con vinos rosados y tintos de la variedad `Tempranillo¿. Se determinó el grado alcohólico, la acidez total, acidez volátil, pH, sulfuroso total, azúcares residuales, ácido málico, ácido láctico, ácido cítrico, y glicerol de los vinos, además de la intensidad colorante, el tono, la concentración de antocianos, y el índice de polifenoles totales en los vinos tintos. Los resultados obtenidos pusieron de manifiesto que la producción de sulfitos no superó valores medios de 1 mg/L, y que los valores de los parámetros analizados se encontraban dentro del rango de valores de los vinos de calidad. La fermentación se realizó con dos tipos de cepas de levaduras diferentes, observándose que la reinoculación a los 3 días del arranque de la fermentación daba origen al mínimo contenido de sulfitos.[EN] In the present work, the production of sulphites from different commercial yeast strains during the fermentation of white, rosé and red wines was studied. For this, an experience was carried out with white wines of the `Tardana¿ variety, and two with rosé and red wines of the `Tempranillo¿ variety. The alcoholic degree, total acidity, volatile acidity, pH, total sulphurous, residual sugars, malic acid, lactic acid, citric acid, and glycerol of the wines were determined, in addition to the colour intensity, the tone, the concentration of anthocyanins, and the total polyphenol index in red wines. The results obtained showed that the production of sulphites did not exceed average values of 1 mg/L, and that the values of the analysed parameters were within the range of values of quality wines. The fermentation was carried out with two different types of yeast strains, observing that the re¿inoculation 3 days after the start of the fermentation gave rise to the minimum content of sulphites.Martínez, J.; Chirivella, C.; Aleixandre-Tudó, JL.; Aleixandre Benavent, JL. (2020). Producción de sulfitos durante la fermentación de vinos blancos de "Tardana" y rosados y tintos de "Tempranillo" en la D.O. Utiel-Requena. Enoviticultura. 64:14-29. http://hdl.handle.net/10251/163588S14296

150 años del descubrimiento del yacimiento cámbrico de Murero (Cadenas Ibéricas, NE España).

The lower-middle Cambrian palaeontological site of Murero (Cadenas Ibéricas, NE Spain) is a classical locality of the Cambrian in Europe. The site was first reported by the French geologist Edouard de Verneuil in 1862, and now it achieves 150 years of geological works contributing to a better knowledge of the Cambrian Period. Murero is an exceptional Lagerstätte because the coexistence of both skeletal and soft-bodied groups along a continuous record of ca. 8 million years, which is subdivided into 14 trilobite zones. Murero was the first palaeontological site in Spain to obtain the highest protection figure (Bien de Interés Cultural, BIC) from the Spanish Administration in 1997. Since then, the educational and social projection of the site is continuously increasing

SEOM clinical guideline for treatment of kidney cancer (2017)

The goal of this article is to provide recommendations about the management of kidney cancer. Based on pathologic and molecular features, several kidney cancer variants were described. Nephron-sparing techniques are the gold standard of localized disease. After a randomized trial, sunitinib could be considered in adjuvant treatment in high-risk patients. Patients with advanced disease constitute a heterogeneous population. Prognostic classification should be considered. Both sunitinib and pazopanib are the standard options for first-line systemic therapy in advanced renal cell carcinoma. Based on the results of two randomized trials, both nivolumab and cabozantinib should be considered the standard for second and further lines of therapy. Response evaluation for present therapies is a challenge

Principles of Biotechnology and Bioengineering in microalgae cultures: importance, technological problems, culture types and systems, growth, limiting factors, selection, isolation, grading and biochemical characterization.

El cultivo masivo de microalgas para la producción de biocombustible alternativo al petróleo, compuestos de valor añadido (CAVA) con aplicaciones químicas o farmacéuticas y como fuente de alimento para una población mundial creciente, sigue siendo uno de los campos más prometedores de la bioingeniería y biotecnología. Sin embargo, todavía queda mucho trabajo por realizar en investigación y desarrollo para optar a todas las magníficas posibilidades que ofrece esta fuente renovable. De este modo, en esta revisión se pretende mostrar los principios referentes al cultivo de microalgas: su importancia, los problemas tecnológicos que todavía quedan por solucionar, todos los aspectos relacionados con sus tipos y sistemas de cultivo, las fases del crecimiento, las ecuaciones de la cinética de duplicación celular, características importantes referentes a la selección y aislamiento de cepas, escalado, métodos de caracterización bioquímica (determinación de clorofilas, proteínas, lípidos, carbohidratos, sílice, etc.) y, finalmente, las especies de microalgas más relevantes.Massive cultivation of microalgae for the production of alternative biofuels, value added compounds with chemical or pharmaceutical applications and as a food source for a growing world population remains one of the most promising fields of bioengineering and biotechnology. However, much work must be done still in research and development to achieve all the possibilities offered by this renewable source. Thus, this review intends to show the principles concerning the cultivation of microalgae: its importance, technological problems still to be solved, all aspects related to their types and systems of cultivation, growth phases, kinetics equations for cell duplication, important aspects related to the selection and isolation of strains, scaling, biochemical characterization methods (determination of chlorophylls, proteins, lipids, carbohydrates, silica, etc.) and finally the most relevant microalgae species.Ciencias Experimentale